Continuity mistake: Marcy's niece asks Bud to take a shower so she can get out of her sticky clothes. Next scene, she's sitting on the couch with a towel on her head. She talks to Bud awhile then gets up and leaves. Shes wearing the same "sticky" clothes and she takes the towel off her head, and her hair is completely dry.
Continuity mistake: Marcy says her parents never let her have a Barbie as a child. In Season 2 episode 14, Guys and Dolls, Al and Steve steal Marcy's Barbie from the basement to sell to buy a new baseball card.
Answer: It's implied that Steve filed for divorce since in s04e16, "You Gotta Know When to Hold 'Em", Marcy says that Steve is suing for alimony. Alimony is something that has to be requested when filing for divorce. Although the show doesn't spend time on the actual legal proceedings of their divorce.
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